/ Thesaurus / B Synonyms of black diamond Find synonyms for: Noun1. carbonado, black diamond, diamond, adamantusage: an inferior dark diamond used in industry for drilling and polishingWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: devout Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language